Indexes of Thermal Comfor in Dairy Cows (Thi) During Summer Months from 2005 to 2016 in Vojvodina Region

Abstract

One of the most important factors of comfort and well-being of animals is a constant ambient temperature. A stressful environment temperature is estimated comparative measurement of air temperature and humidity (eng. Temperature-Humidity Index, THI). The aim of this study was to determine the mean peak value of THI index in Vojvodina in the period 2005-2016 years. The research results show that the mean value of THI index measured at 14 o'clock in the warmest part of the day exceeds the value of 72, which is considered the upper limit of the thermal comfort of the cows. The linear regression equation shows that from 2005 to 2016 there is a trend increase in mean maximum THI index in all three summer months in June, an increase of 0.17; in July to 0.29 in August, and by about 0.51 units per year. The number of days in which the THI indexed outside the thermal comfort of the cows more than 12 hours per day has increased from 2005 to the present. In 2007 and 2012 there were extremely negative conditions in which the THI index was above the optimum for more than 12 hours a day. During the summer thermal comfort of cows in Vojvodina was significantly compromised, with further growth.

Jedan od najvažnijih činilaca komfora i dobrobiti životinja je stalna ambijentalna temperatura. Stresogenost temperature ambijenta se procenjuje uporednim merenjem temperature vazduha i vlažnosti vazduha (eng. Temperature-Humidity Index, THI). Cilj ovog rada je da se utvrde srednje maksimalne vrednosti THI indeksa na teritoriji AP Vojvodine u periodu 2005-2016 godina. Rezultati istraživanja pokazuju da srednja vrednost THI indeksa izmerena u 14 časova u najtoplijem delu dana prevazilazi vrednost 72, koja se smatra gornjom granicom termalnog komfora kod krava. Linearna regresiona jednačina pokazuje da od 2005 do 2016 godine postoji trend porasta srednjeg maksimalnog THI indeksa u sva tri letnja meseca: u junu porast za 0,17; u julu za 0,29 i u avgustu za oko 0,51 jedinica godišnje. Broj dana u kojima je THI indek izvan termalnog komfora krava duže od 12 časova dnevno je u porastu od 2005 godine do danas. U 2007. i 2012 godini postojali su ekstremno negativni uslovi u kojima je THI indeks bio iznad optimuma više od 12 sati dnevno. Tokom letnjih meseci termalni komfor krava na teritoriji AP Vojvodine je značajno ugrožen, sa daljom tendencijom porasta.